Add a nice install paths for module SDKs and exports.

Following how NDK also creates its own install path.

Bug: 142935992
Test: cc_sdk_test.go, java_sdk_test.go
Change-Id: I98a3656903f37f6d7c90e6cf609431b2461a6161
diff --git a/sdk/sdk.go b/sdk/sdk.go
index 14e44bf..db71575 100644
--- a/sdk/sdk.go
+++ b/sdk/sdk.go
@@ -281,7 +281,9 @@
 		}
 
 		// Generate the snapshot from the member info.
-		s.snapshotFile = android.OptionalPathForPath(s.buildSnapshot(ctx, sdkVariants))
+		p := s.buildSnapshot(ctx, sdkVariants)
+		s.snapshotFile = android.OptionalPathForPath(p)
+		ctx.InstallFile(android.PathForMainlineSdksInstall(ctx), s.Name()+"-current.zip", p)
 	}
 }